"I didn't realize it would blow up and become the big deal it has become," Sullivan, 45, tells PEOPLE. "Neither of us have been on the 'I'm an activist' train, and I still don't think we really are, because all we're doing is just living our lives. But it just so happens that our spot is entering people's living rooms that normally probably wouldn't let us into their homes, and they don't really have a choice."

"When at the end of the day," Monahan, 44, adds, "all we're trying to do is pay for preschool and our mortgage! But we're happy to be that couple who put ourselves out there to just show that families come in all shapes and sizes."